Voronov’s laboratory (224) is located on the 2nd floor of the Research I building in NDSU Research and Technology Park (1735 Research Park Drive, Fargo, ND, 58108-6050)
Our group is focused on the design, properties, and applications of a new class of self-assembling macromolecules: amphiphilic invertible polymers (AIPs). They have been designed by combining hydrophobic and hydrophilic constituents distributed along the polymer backbone.
Given that AIP macromolecule fragments’ incompatibility is achieved on a smaller length scale it is possible to achieve greater tunability of the assemblies’ formation. The latter has been approached by synthesizing amphiphilic macromolecules containing a precisely controlled number of hydrophilic and hydrophobic short fragments with a well-defined length. The control over the self-assembly additionally benefits from having the hydrophilic and hydrophobic fragments distributed alternately in the AIP macromolecule.
AIPs form invertible polymeric micelles or self-arranged aggregates of micelles in response to tuning of the polymer concentration and environmental polarity. The resulting invertible complex self-assembled nanostructures are functional in both polar and non-polar environments, giving these micelles potentially broad use in many chemical and biochemical applications.
We used self-assembled AIPs as nanoreactors for the synthesis of smart nanoparticles that have a protective shell made from hydrophilic and hydrophobic polymeric fragments, and, thus, are highly stable in polar and non-polar environments. We confirmed ability of self-assembled AIPs to encapsulate and concentrate insoluble substances that makes the their application as smart polymeric nanocontainers especially promising for the pharmaceutical industry (controlled release, targeted devices), agriculture (micronutrient delivery, development of fertilizers), and cosmetics (encapsulation of functional ingredients and their delivery).
In early studies we documented that the AIP macromolecules based on polyethylene glycol and aliphatic dicarboxylic acids form micelles, and self-assemble in micellar aggregates inversely responding to the changing AIP concentration and solvent polarity (scheme below).
Our current research is divided into several areas:
1. Novel assemblies from AIP macromolecules. By modifying the AIP composition, medium and self-assembly conditions, we observe new properties of AIP superstructures.
2. Mechanism of AIP macromolecules self-assembly. We are working on phase diagram for the AIP self-assembled aggregates using systematical NMR studies and scattering techniques. Careful analysis should also provide us with mechanism of the invertibility of the self-assembly by changing polarity.
3. Bio-and pharmaceutical applications. We are working on developing the AIP-based nanoextractors, nanovehicles and nanocontainers which allow specific interactions with cell membrane and, possibly, delivery of poorly soluble lipophilic drugs. The ability of AIP assemblies “to cross interface” between polar and non-polar medium is considered.
4. Organometallic applications. Assuming that self-assembled AIP superstructures provide microphase-separated domains of specific size, we use them as nanovessels for the reactions both in polar and non-polar medium. It is possible to synthesize noble metal nanoparticles and semiconducting quantum dots using AIPs architectures.